Null models of geographic range size evolution reaffirm its heritability

Area of Science:

• Evolutionary Biology
• Biogeography
• Speciation Research

Background:

• Allopatric speciation models predict divergent range sizes for daughter species.
• Observed range sizes of sister species are often more similar than predicted.
• This similarity, termed symmetry, has been linked to range size heritability.

Purpose of the Study:

• To investigate if sister species' range sizes become more similar after speciation.
• To test the hypothesis that geographic range size is heritable.
• To evaluate the implications of range size heritability for comparative evolutionary analyses.

Main Methods:

• Compared observed range size differences between sister species against null models of range evolution.
• Assessed range size heritability using a symmetry approach.
• Utilized a phylogenetic signal test on North American bird range size data.

Main Results:

• Sister species exhibit less range size difference than expected under null models.
• Geographic range size demonstrates heritability under both symmetry and phylogenetic signal tests.
• The degree of range size similarity between sister species is greater than predicted by standard models.

Conclusions:

• Geographic range size is heritable, with sister species tending towards similar distributions post-speciation.
• Null models for range evolution and heritability require explicit evolutionary models.
• Comparative methods may yield inaccurate results if the unique inheritance pattern of range size is not considered.